JP5919864B2 - engine - Google Patents

Description

  The present invention relates to an engine including a gas-liquid separator that gas-liquid separates oil in blow-by gas in an engine case, and a negative pressure pump that makes the pressure in the engine case negative.

  Along with the operation of the engine, a part of the unburned mixed gas in the combustion chamber passes through the sliding gap between the piston and the cylinder and flows out into the engine case (crankcase) as blow-by gas. Such blow-by gas is re-supplied as engine fuel through the blow-by gas passage. However, since oil in the engine case is mixed in the blow-by gas, it is necessary to separate the oil from the blow-by gas before re-supply. .

  As such a blow-by gas processing apparatus, Patent Document 1 discloses that a plurality of fins are radially fixed to the outer periphery of a balancer shaft, and the blow-by gas rotates in the axial direction on the balancer shaft and rotates together with the balance shaft. A fin has been proposed that separates oil and blow-by gas in blow-by gas by the action of centrifugal force.

JP 2009-2222044 A

  However, since the blow-by gas processing apparatus described in Patent Document 1 has a structure that causes the blow-by gas to flow in the axial direction of the balancer shaft, an increase in the size of the apparatus cannot be avoided.

  On the other hand, in an engine, in order to suppress a pumping loss that is a resistance to the reciprocating motion of the piston, a negative pressure pump that sucks air in the engine case and makes the pressure in the engine case negative may be installed. is there. However, this negative pressure pump has a tendency that the amount of work increases as the amount of negative pressure increases, and the operating efficiency and durability decrease.

  The blow-by gas processing apparatus described in Patent Document 1 can perform a centrifugal separation function, and can increase the discharge amount of air containing blow-by gas even if the rotation speed of the fins is increased. Does not have. Therefore, in this blow-by gas processing apparatus, the auxiliary action of the negative pressure pump cannot be achieved, and the operating efficiency of the negative pressure pump cannot be improved.

  An object of the present invention has been made in consideration of the above-described circumstances, and is a negative pressure pump that can suitably gas-liquid-separate oil in blow-by gas and makes the inside of the engine case negative to suppress pumping loss. It is an object to provide an engine capable of improving the operation efficiency and durability of the engine.

The present invention is an engine having a rotary gas-liquid separator that gas-liquid separates oil in blow-by gas in the engine case, and a negative pressure pump that makes the pressure in the engine case negative. A gear member driven by engine power is provided in the engine case, the gas-liquid separator configured as a centrifugal pump is provided in the gear member, and the negative pressure pump is connected to a shaft portion of the gear member. The gas-liquid separator has a function of discharging and depressurizing air containing blow-by gas, and the negative pressure pump sucks air containing blow-by gas from which oil has been separated by the gas-liquid separator. In addition , a function of further reducing the pressure in the engine case, which has been decompressed by the gas-liquid separator, to a negative pressure is provided .

  According to the present invention, the rotary gas-liquid separator can suitably gas-liquid-separate the oil in the blow-by gas by the action of centrifugal force, and the gas-liquid separator depressurizes the air containing the blow-by gas. Since the negative pressure pump is supplemented by providing the function, the work efficiency and durability of the negative pressure pump that makes the inside of the engine case negative to suppress pumping loss can be improved.

1 is a left side view showing a motorcycle equipped with an embodiment of an engine according to the present invention. The right view which shows the engine of FIG. The fragmentary sectional view which follows the III-III line of FIG. Sectional drawing which shows the gas-liquid separator of FIG. The arrow line view which follows the VV line of FIG. FIG. 6 is an arrow view taken along line VI-VI in FIG. 4. Sectional drawing which shows the 3rd and 4th blow-by-gas channel | path etc. through which the blow-by gas from which the oil was isolate | separated by the gas-liquid separator of FIG. 4 flows. Sectional drawing which follows the VIII-VIII line of FIG.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a left side view showing a motorcycle equipped with an embodiment of an engine according to the present invention. In the present embodiment, expressions of front and rear, top and bottom, and left and right are based on a passenger who rides the motorcycle.

  As shown in FIG. 1, a motorcycle 1 has a body frame 2, and a head pipe 3 is provided in front thereof. The head pipe 3 is provided with a steering mechanism 7 including a pair of left and right front forks 5 and a handle bar 6 which are provided with a suspension mechanism (not shown) and rotatably support the front wheel 4. It is steered to turn left and right.

  On the other hand, the vehicle body frame 2 is, for example, of a twin tube type, and is expanded to the left and right immediately after the head pipe 3 and then serves as a main frame 8 that also serves as a pair of left and right tank rails extending parallel to each other and rearwardly downward. And a pair of left and right center frames 9 connected to the rear ends of the main frames 8 and extending substantially in the vertical direction, and a pair of left and right seat rails 10 extending rearward from the rear ends of the center frames 9. Composed.

  A fuel tank 11 is disposed above the main frame 8, and a rider seat 12A and a pillion seat 12B are disposed above and below the vehicle, respectively. Further, a pivot shaft 13 is installed substantially at the center lower portion of the center frame 9, and a swing arm 14 is pivotally attached to the pivot shaft 13 so as to be swingable around the pivot shaft 13, and a rear end is provided at the rear end of the swing arm 14. The wheel 15 is rotatably supported. An engine 16 as an internal combustion engine is suspended and mounted on the main frame 8 or the like below the fuel tank 11 at the lower center of the vehicle body between the front wheels 4 and the rear wheels 15.

  Further, in the motorcycle 1, the front portion of the vehicle body is covered with a streamlined cowling 17 to reduce air resistance during traveling and to protect the rider from traveling wind pressure. 1 is an exhaust pipe that discharges exhaust gas from the engine 16, and an exhaust muffler 18B is connected to the rear end of the exhaust pipe 18A.

  As shown in FIG. 2, the engine 16 is a four-cycle multi-cylinder engine, for example, a four-cycle in-line four-cylinder engine. Composed. The crankcase 22 is of a split type, and is divided into, for example, two parts in the vertical direction in FIG. 2 and includes an upper crankcase 22A and a lower crankcase 22B. A cylinder block 21 is installed on the upper part of the upper crankcase 22A, and an oil pan 24 is installed on the lower part of the lower crankcase 22B.

  The cylinder block 21 is inclined slightly forward from the upright, and a bearing portion (not shown) is formed on the inside of the mating surface 23 of the upper crankcase 22A and the lower crankcase 22B and divided into upper and lower parts. A crankshaft 25 extending in the width direction of the engine 16 is rotatably supported by these bearing portions.

  A piston (both not shown) is connected to the crankshaft 25 via a connecting rod. A piston is housed in the cylinder block 21 so as to be slidable substantially in the vertical direction in the figure. A combustion chamber (not shown) is formed in the space between the cylinder head 20 and the piston. The piston is reciprocated by the combustion of the air-fuel mixture in the combustion chamber, and the reciprocating motion of the piston is converted into rotational motion by the crankshaft 25.

  In the crankcase 22, a counter shaft 26, a driven shaft 27, and a generator shaft 28 are disposed behind the crankshaft 25 in a side view of the engine 16. Among these, the crankshaft 25 and the countershaft 26 are pivotally supported on the mating surface 23 of the upper crankcase 22A and the lower crankcase 22B. Further, the generator shaft 28 is disposed obliquely in front of the counter shaft 26. The crankshaft 25, the countershaft 26, the drive shaft 27, and the generator shaft 28 described above extend in the width direction of the engine 16 (that is, the vehicle width direction of the motorcycle 1) and are accommodated in the crankcase 22.

  A primary drive gear 29 is provided on the crankshaft 25 so as to rotate integrally. The primary drive gear 29 meshes with a primary driven gear 30 that is rotatably supported by the counter shaft 26. The counter shaft 26 is provided with a clutch mechanism (not shown) coupled to the primary driven gear 30 at the shaft end, and a plurality of stages of mission drive gear (not shown) are mounted on the counter shaft 26. These mission drive gears mesh with a plurality of mission driven gears (not shown) mounted on the drive shaft 27. These mission drive gear and mission driven gear together with a shift mechanism (not shown) constitute a transmission mission mechanism.

  The shaft end of the drive shaft 27 protrudes outside the crankcase 22, and a drive sprocket (not shown) is fixed to the shaft end of the drive shaft 27. A driven sprocket 31 is fixed to the rear wheel 15 as shown in FIG. 1, and a drive chain 32 is wound between the drive sprocket and the driven sprocket 31.

  Accordingly, the rotational force of the crankshaft 25 of the engine 16 shown in FIGS. 1 and 2 (that is, the driving force of the engine 16) is transmitted to the counter shaft 26 via the primary drive gear 29, the primary driven gear 30 and the clutch mechanism. The signal is transmitted from the counter shaft 26 to the drive shaft 27 through the transmission mission mechanism. The rotational force of the crankshaft 25 transmitted to the drive shaft 27 is transmitted to the rear wheel 15 via the drive sprocket, the drive chain 32 and the driven sprocket 31.

  Further, as shown in FIGS. 2 and 3, the generator shaft 28 is provided with a generator driven gear 33 so as to rotate together. Accordingly, the rotational force of the crankshaft 25 is transmitted to the generator shaft 28 through the primary drive gear 29, the primary driven gear 30, and the generator driven gear 33 in order. As a result, a generator (not shown) attached to the generator shaft 28 so as to rotate integrally is rotationally driven to generate electric power.

  Here, the generator driven gear 33 provided on the generator shaft 28 has the same specifications (the same diameter and the same number of teeth) as the primary drive gear 29 provided on the crankshaft 25. Therefore, the distance between the generator shaft 28 and the counter shaft 26 is equal to the distance between the crank shaft 25 and the counter shaft 26, and the generator shaft 28 is the same as the crank shaft 25 regardless of the number of teeth of the primary driven gear 30. It is possible to rotate in the same direction at a rotational speed of.

  2 and 3, a breather chamber 35, which is a part of the internal space of the crankcase 22, is provided above the generator shaft 28 above the crankcase 22 in the engine 16, and this breather chamber. A gas-liquid separator 36 is disposed in 35, and a negative pressure pump 37 is connected to the gas-liquid separator 36 and installed outside the crankcase 22.

  The gas-liquid separator 36 gas-liquid-separates oil mixed in blow-by gas flowing into the crankcase 22 from a combustion chamber (not shown) through a sliding gap between a cylinder (not shown) and a piston of the cylinder block 21. It is. In order to efficiently perform gas-liquid separation by the gas-liquid separator 36, the breather chamber 35 that accommodates the gas-liquid separator 36 is provided in the crankcase 22 at an upper portion with a small amount of oil. The negative pressure pump 37 sucks air containing blow-by gas existing in the crankcase 22 in order to suppress a pumping loss (resistance to the reciprocating motion of the piston), which is one of mechanical losses. The pressure in 22 is maintained at a negative pressure.

As shown in FIGS. 3 and 4, the gas-liquid separator 36 includes a centrifugal pump provided with an upstream fin 39 and a downstream fin 40 that are integrally rotatable with a gear member 38 driven by the power of the engine 16. Configured as The upstream fin 39 and the downstream fin 40 extend radially outward from the shaft portion 43 toward the tooth portion 45 between the shaft portion 43 and the tooth portion 45 of the gear member 38, and the teeth in the gear member. The oil in the blow-by gas is centrifuged in the inner region of the part 45.
More specifically, the gas-liquid separator 36 includes a gear member 38 having an upstream fin 39, a plate member 41 having a downstream fin 40 that is rotatably coupled to the gear member 38, and a gear member. 38, and a cover member 42 that is rotatably and integrally attached to the opposite side of the plate member 41.

  In the gear member 38, a hub portion 44 extends in a plate shape from the periphery of a shaft portion 43 having a hollow structure, and a tooth portion 45 having teeth 45A is formed on the outer periphery of the hub portion 44. A ring-shaped fitting protrusion 46 is integrally formed on the rear surface 44B of 44. The plate member 41 is fitted to the fitting projection 46, and the plate member 41 is rotationally coupled to the gear member 38 using a bolt 34 (FIG. 6) or the like.

  The shaft portion 43 of the gear member 38 is rotatably supported by the crankcase 22 via a bearing 47. Further, the shaft portion 48 of the plate member 41 is also rotatably supported by the crankcase 22 via the bearing 47. The gear member 38 is rotationally driven by the power of the engine 16 when the teeth 45 </ b> A of the tooth portion 45 are meshed with a gas-liquid separator drive gear 49 that is rotationally and integrally coupled to the generator shaft 28.

  At this time, the gas-liquid separator drive gear 49 has a smaller diameter than the generator-driven gear 33 and the gear member 38 has a larger diameter than the gas-liquid separator drive gear 49. It is rotationally driven in a state of being decelerated from 28. The reduction ratio of the gear member 38 ensures both improvement in gas-liquid separation performance by the gas-liquid separator 36 and prevention of over-rotation of the negative pressure pump 37 coupled to the shaft portion 43 of the gear member 38 as will be described later. Determined to be able to.

  As shown in FIGS. 4 and 5, a plurality of upstream fins 39 extending radially outward of the gear member 38 are formed radially on the shaft portion 43 on the front surface 44 </ b> A of the hub portion 44 of the gear member 38. Has been. A cover member 42 having a substantially disk shape is coupled to the hub portion 44 of the gear member 38 so as to cover these upstream fins 39 and to be integrally rotated with the gear member 38. A first blow-by gas passage 51 is formed between the front surface 44 </ b> A of the hub portion 44 of the gear member 38 and the cover member 42. A blow-by gas suction port 50 is formed between the inner periphery of the cover member 42 and the shaft portion 43 of the gear member 38.

  The hub portion 44 of the gear member 38 has a plurality (three in the present embodiment) of outflow openings 56 in the circumferential direction of the gear member 38 at the radially outer position of the upstream fin 39. The outflow opening 56 communicates with the first blow-by gas passage 51 and also communicates with a second blow-by gas passage 52 formed between the back surface 44B of the hub portion 44 of the gear member 38 and the plate member 41. The downstream fin 40 is disposed in the second blow-by gas passage 52.

  That is, as shown in FIGS. 4 and 6, the plate member 41 has the downstream fin 40 extending radially outward of the plate member 41 on the inner surface on the gear member 38 side, and the shaft portion 48 of the plate member 41. A plurality of radial lines are formed at the center. At least a part of the downstream fin 40 (radially outer portion in the present embodiment) is provided so as to overlap the outflow opening 56 when viewed in the axial direction of the gear member 38.

  Therefore, the upstream fin 39 and the downstream fin 40 are disposed on both sides of the hub portion 44 of the gear member 38. As shown in FIGS. 4 to 6, the upstream fin 39 is formed to be convexly curved with respect to the rotation direction P of the gear member 38, so that air containing blow-by gas flows from the suction port 50 to the gear member 38. Discharge radially outward. Further, the downstream fin 40 is formed to be concavely curved with respect to the rotation direction P of the gear member 38 and the plate member 41, and the air including the blowby gas is discharged from the outflow opening 56 in the radial direction of the gear member 38 and the plate member 41. Scrap inward and discharge.

  As a result, the air containing the blow-by gas in the crankcase 22 is sucked into the first blow-by gas passage 51 from the suction port 50 of the gas-liquid separator 36 through the breather chamber 35 (arrow A in FIG. 4). 1 flows in the blow-by gas passage 51 from the radially inner side to the outer side along the upstream fin 39 (arrow B in FIG. 5), passes through the outflow opening 56 on the radially outer side of the upstream fin 39, and flows into the downstream fin. 40 flows into the second blow-by gas passage 52 (arrow C in FIG. 4 and FIG. 5), and the second blow-by gas passage 52 extends from the radially outer side to the inner side along the downstream fin 40. Flows (arrow D in FIG. 6).

  The shaft portion 43 of the gear member 38 is configured in a hollow structure as described above, and the hollow portion of the shaft portion 43 is configured as the third blow-by gas passage 53. The third blow-by gas passage 53 communicates with the discharge side of the downstream fin 40 in the second blow-by gas passage 52, and takes in air containing blow-by gas discharged from the radially inner side of the downstream fin 40 (FIG. 4). Arrow E). The air containing the blow-by gas taken into the third blow-by gas passage 53 passes through a discharge port 57 formed at the tip portion of the shaft portion 43 of the gear member 38, as will be described later, a fourth blow-by gas passage 54 (FIG. 7). And discharged (arrow F in FIG. 4).

  While the air containing the blow-by gas flows radially outward in the first blow-by gas passage 51 by the upstream fin 39, the oil in the blow-by gas and the blow-by gas are separated into gas and liquid due to the difference in specific gravity due to the centrifugal force. Is done. The air containing the blow-by gas from which the oil has been separated flows into the second blow-by gas passage 52 through the outflow opening 56 and is discharged from the discharge port 57 through the third blow-by gas passage 53 as described above. On the other hand, the oil separated from the blow-by gas is scattered from within the first blow-by gas passage 51 and reaches the tooth portion 45 of the gear member 38 (arrow O in FIGS. 4 and 5).

  Here, as shown in FIG. 4, in the axial direction of the gear member 38 (that is, the width direction of the teeth 45 </ b> A of the gear member 38), at least a part (all in the present embodiment) of the upstream fins 39 is the gear member 38. Provided at a position overlapping the tooth portion 45 and the tooth 45A. The tooth portion 45 is formed with an oil hole 58 that penetrates in the radial direction of the gear member 38 from the root of the tooth 45 </ b> A toward the upstream fin 39. Therefore, the oil separated from the blow-by gas scatters from the first blow-by gas passage 51 and reaches the tooth portion 45 of the gear member 38, and then flows out through the oil hole 58 to lubricate the teeth 45A.

  Further, the downstream fin 40 discharges air containing blowby gas from the radially inner side to the outer side of the gear member 38 in the first blowby gas passage 51, and the downstream fin 40 has the second blowby gas passage. In 52, the discharge amount is set to be larger than the discharge amount by which the air including the blow-by gas is scraped from the radially outer side of the gear member 38 to the inner side. Moreover, the capacity of the third blow-by gas passage 53 of the shaft portion 43 of the gear member 38 is set to be sufficiently larger than the flow passage area of the discharge portion of the second blow-by gas passage 52. For this reason, the gas-liquid separator 36 has a function of depressurizing the air in stages while sequentially discharging the air containing the blow-by gas from the first blow-by gas passage 51 to the second blow-by gas passage 52. . As a result, in the air containing blowby gas, a pressure difference is generated between the suction port 50 and the discharge port 57 of the gas-liquid separator 36.

  As shown in FIGS. 7 and 8, the air containing the blow-by gas discharged from the discharge port 57 of the gas-liquid separator 36 communicates with the discharge port 57 and is formed in the crankcase 22 and the heat insulating wall 59. The air cleaner 60 reaches the negative pressure pump 37 through the four blow-by gas passages 54 and is further depressurized by the negative pressure pump 37, and then passes through the fifth blow-by gas passage 55 formed in the crankcase 22 and the heat insulating wall 59. Flow into. Thus, the negative pressure pump 37 is disposed in the blow-by gas path from the gas-liquid separator 36 to the air cleaner.

  As shown in FIG. 3, the negative pressure pump 37 includes a drive shaft 61 that is connected to the tip of the shaft portion 43 of the gear member 38 of the gas-liquid separator 36 in a rotationally integrated manner, It is driven by 16 powers. The negative pressure pump 37 is a Roots type blower, and the pressure in the crankcase 22 is reduced to negative pressure by sucking air containing blowby gas from which oil has been separated by the gas-liquid separator 36. Thereby, the pumping loss as a resistance to the reciprocating motion of the piston in the engine 16 is suppressed.

  As shown in FIGS. 7 and 8, the fourth blow-by gas passage 54 communicates with a bypass passage 62 that bypasses the negative pressure pump 37, and this bypass passage 62 communicates with the air cleaner 60 via the relief valve 63. Has been. When the pressure in the fourth blow-by gas passage 54 increases with respect to the pressure (atmospheric pressure) in the fifth blow-by gas passage 55 because the blow-by gas suddenly increases in the crankcase 22, the relief valve 63 is Without opening the air containing the blow-by gas in the fourth blow-by gas passage 54 to the negative pressure pump 37, the air is led to the air cleaner through the bypass passage 62 and in the fourth blow-by gas passage 54, and thus in the crankcase 22. It is comprised so that the pressure of may be reduced.

With the configuration as described above, according to the present embodiment, the following effects (1) to (9) are achieved.
(1) As shown in FIGS. 3 and 4, since the rotary gas-liquid separator 36 is disposed in the breather chamber 35 communicating with the crankcase 22, the gas-liquid separator 36 allows the crankcase to The oil in the blow-by gas in 22 can be suitably separated by the action of centrifugal force. Furthermore, since the gas-liquid separator 36 has a function of discharging air containing blow-by gas to reduce the pressure, the auxiliary function of the negative pressure pump 37 is achieved. The work efficiency and durability of the negative pressure pump 37 can be improved.

  (2) Since the upstream fin 39 and the downstream fin 40 of the gas-liquid separator 36 are provided so as to be integrally rotatable with the gear member 38 driven by the power of the engine 16, the gas-liquid separator 36 is made space efficient. The negative pressure pump 37 can be driven by the power of the engine 16 because the negative pressure pump 37 is connected to the gear member 38 so as to be integrally rotated.

  (3) Since the gas-liquid separator 36 is configured as a centrifugal pump provided with the upstream fin 39 and the downstream fin 40, the oil in the blow-by gas and the blow-by gas are separated from each other by the difference in specific gravity due to the centrifugal force. Liquid separation can be performed.

  (4) Since the oil hole 58 penetrating from the tooth bottom of the tooth 45A toward the upstream fin 39 is formed in the tooth portion 45 of the gear member 38 in the gas-liquid separator 36, the upstream fin 39 prevents the blow-by gas from The separated oil can be guided to the teeth 45A through the oil holes 58, whereby the teeth 45A can be well lubricated.

  (5) The upstream fin 39 and the downstream fin 40 are provided on both sides of the hub portion 44 of the gear member 38 in the gas-liquid separator 36, and the outflow opening 56 is formed in the hub portion 44. Therefore, the oil in the blow-by gas can be separated while the air containing the blow-by gas reaches the outflow opening 56 from the upstream fin 39, and further, the air containing the blow-by gas passes through the outflow opening 56 from the upstream fin 39. By flowing to the downstream fins 40, this air can be decompressed stepwise.

  (6) The radially outer portion of the downstream fin 40 in the gas-liquid separator 36 is configured to overlap the outflow opening 56 formed in the hub portion 44 of the gear member 38 when viewed in the axial direction of the gear member 38. Yes. For this reason, the air containing blowby gas can be easily flowed through the outflow opening 56 into the second blowby gas passage 52 in which the downstream fins 40 are disposed.

  (5) Air containing blow-by gas flows from the radially inner side to the outer side along the upstream fin 39 in the first blow-by gas passage 51, and along the downstream fin 40 in the second blow-by gas passage 52. By flowing from the radially outer side toward the inner side, the first blow-by gas passage 51 and the second blow-by gas passage 52 can be configured in a U-turn structure. As a result, space saving of the gas-liquid separator 36 can be realized.

  (8) In the gas-liquid separator 36, the discharge flow rate of the air containing the blow-by gas by the upstream fin 39 is set to be larger than the discharge flow rate by the downstream fin 40, and the discharge portion of the second blow-by gas passage 52 The flow path area is set larger than the capacity of the third blow-by gas passage 53. Therefore, the gas-liquid separator 36 can reliably depressurize the air containing the blow-by gas, and as a result, the gas-liquid separator 36 can perform the auxiliary action of the negative pressure pump 37.

  (9) Since the shaft portion 43 of the gear member 38 in the gas-liquid separator 36 has a hollow structure, and the hollow portion of the shaft portion 43 is configured as the third blowby gas passage 53, the third blowby gas passage 53 is limited. Can be realized in a given space.

  Although the embodiments have been described above, the present invention is not limited to the specific configurations of the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, although the negative pressure pump 37 has been described as a roots type blower, it may be a gear type, plunger type, or lithorme type blower. The negative pressure pump 37 is driven by the power of the engine 16 via the gas-liquid separator 36. However, the negative pressure pump 37 may be driven by an electric motor or by using exhaust pressure as a drive source.

16 Engine 22 Crankcase (Engine case)
36 Gas-liquid separator 37 Negative pressure pump 38 Gear member 39 Upstream fin 40 Downstream fin 43 Shaft 44 Hub 45 Tooth 45A Tooth 53 Third blow-by gas passage 56 Outflow opening 58 Oil hole 60 Air cleaner

Claims (8)

An engine having a rotary gas-liquid separator that gas-liquid separates oil in blow-by gas in the engine case, and a negative pressure pump that makes the pressure in the engine case negative.
A gear member driven by engine power is provided in the engine case, the gas-liquid separator configured as a centrifugal pump is provided in the gear member, and the negative pressure pump is connected to a shaft portion of the gear member. ,
The gas-liquid separator has a function of discharging and depressurizing air containing blow-by gas,
It Functions The vacuum pump, which sucks air containing blowby gas from which the oil has been separated by the gas-liquid separator, to further vacuum pressure in the depressurized the engine casing by the gas-liquid separator engine, comprising the. The gas-liquid separator is provided so as to be integrally rotatable with a gear member driven by engine power, and a negative pressure pump is integrally connected to the shaft portion of the gear member. Engine. The gas-liquid separator is a centrifugal pump provided with fins extending radially outward from the shaft portion toward the tooth portion between a shaft portion and a tooth portion of a gear member driven by engine power. The engine according to claim 1 or 2, wherein At least a part of the fin is provided at a position overlapping the teeth of the gear member in the axial direction of the gear member, and the gear member is provided with an oil hole penetrating in a radial direction from the tooth bottom toward the fin. The engine according to claim 3, wherein The centrifugal pump includes an upstream fin and a downstream fin across the hub portion of the gear member, and blow-by gas passes through an outflow opening formed in the hub portion outside the upstream fin, The engine according to claim 3 or 4, wherein the engine is configured to flow from the upstream fin to the downstream fin. The engine according to claim 5, wherein the downstream fin is provided so as to at least partially overlap with an outflow opening formed in a hub portion of the gear member as viewed in the axial direction of the gear member. In the centrifugal pump, the discharge flow rate by the upstream fin is set larger than the discharge flow rate by the downstream fin, and blow-by gas flows from the radially inner side to the outer side along the upstream fin, and the downstream fin The engine according to claim 5, wherein the engine is configured to flow from the radially outer side toward the inner side along the line. The hollow portion formed in the shaft portion of the gear member is configured as a blow-by gas passage, and the blow-by gas passage is configured to communicate with the discharge side of the downstream fin. The engine according to claim 1.

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